What Size Space Heater Do I Need?



Whether you’re buying a new space heater or replacing an existing one, obtaining the correct size is vital. A space heater that is too small will run without ever heating the space enough which will be inefficient and cost you in the long run. If you choose a heater that is too big, you'll spend more money than necessary. Therefore, it is important to choose the correct size space heater. How do you do this? Keep reading to find out how to determine what size space heater you need.

What Size Space Heater do I Need

What Type of Space Heater Do I Need?

There are several types of space heaters on the market. To help you determine the best kind for you, we’ve broken each type down and where they perform best.

Infrared Heaters

These are designed to provide direct heat to objects and people by emitting infrared rays that warm objects around them. Since they offer direct heat, they are perfect for spot heating specific areas in a room.

These types of heaters are silent and can heat up to 1000 square feet, making them useful for many users. Infrared space heaters are ideal for heating:

  • Small rooms
  • Living rooms
  • Bedrooms
  • Offices
  • Garages & workshops

Convection Space Heaters

Convection heaters are filled with heat transfer oil that radiates heat from the external surface area. As a result, these space heaters are ideal for heating large rooms. In addition, they have a thermostat that regulates the heat before it's dispersed through the room using natural airflow. 

Due to their mode of operation, convection heaters work best where quick heat is not a priority. Such places include:

  • Small rooms
  • Living rooms
  • Bedrooms
  • Offices
  • Garages & workshops

However, these types of heaters are not ideal in areas with pets or children as they are hot to the touch. 

Micathermic Heaters

These types of heaters are hybrid and produce 80% convection heat and 20% direct radiant heat. In addition, micathermic heaters are portable, with most models being wall mountable.

They utilize airflow to heat a space like convection heaters, and are suitable if you have bad allergies. However, these heaters are hot to the touch and therefore not ideal in areas near pets and kids. Micathermic space heaters work well in:

  • Bathrooms
  • Bedrooms
  • Offices
  • Other small rooms

Ceramic Space Heaters

These are fan-forced and the most versatile types of space heaters on the market. In addition, ceramic space heaters are available in small and large sizes, making them easy to find one for your specific room. 

These heaters are cool to touch and hence safe for use in rooms with kids and pets. However, they do produce a lot of noise which can be a deterring factor. You can use these heaters in:

  • Offices
  • Living rooms
  • Bedrooms if you don't mind the noise

How to Determine What Size Space Heater I Need

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Before buying a space heater, determine its size to ensure it produces enough British thermal units (BTUs) to heat your intended room. You can size a space heater by following the steps below.

Measure the Size of the Room

The first thing you need to do is measure the room's size where you'll use the space heater. Take the length and the width of the room and multiply the two measurements to get the room's size in square feet. For instance, if the width is 12ft and the length is 12ft, the room will be 144 square feet. 

determine the Wattage of the heater

Now calculate how much wattage your room needs. A general guideline to use is each square foot needs 10 watts. Therefore, if you have a 144 square feet room, you’ll want a space heater with 1,440 watts. 

Convert Watts to BTU

Since the standard form of measurement for heaters is BTU, you need to convert the required room wattage into BTU. BTU stands for British Thermal Unit, and is a form of measurement used to measure energy. It's commonly used in heating and air conditioning units. 

One watt is equivalent to 3.41 BTUs. Therefore, you need to multiply your room's wattage by 3.41 BTUs. In this case, your 1440 square feet room requires a space heater with 4,910 BTUs. 

take note of the room features

Certain features in a room can also affect the how many BTUs you should look for. For example: 

  • A room with more windows may be drafty and will require a more robust space heater
  • Cemented or tiled rooms are colder and might need a more powerful heater
  • A well-ventilated room will warm up quickly
  • A room with a low ceiling will warm up quickly and won’t require a powerful space heater
  • A room with a crowd of people will warm up quickly and requires less BTUs
  • A room with few windows will warm up quickly and will require less BTUs

Hopefully, the above considerations will help answer you determine what size space heater you need. Make sure while shopping you also keep in mind safety features you need, as space heaters can be a fire hazard if not correctly used.

As a precaution, don't place the heater near long-flowing curtains or other highly flammable items. In addition, make sure you turn off your heater before leaving the room. Also be sure to avoid leaving kids or pets in a room with a space heater. 

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Bottom Line

As discussed above, different types of heaters have various benefits. After determining what size space heater you need for your room, consider other factors such as the heating technology, like convection or infrared, cost, and preferred safety features.

NorTex is here for all of your space heating needs. For any questions regarding what kind or size of space heater is best for you, feel free to contact us and we can help you find your perfect heater.

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